108. Not sure where you're getting your information, but...

...the assault weapon ban did not cause multiple homicides to drop by 60%. Not even close. Handguns are used in the vast majority of homicides - assault weapons like AR-15s account for about 1% of firearm murders. In fact, according to a study published by the National Institute of Justice (the R & D agency within the US DOJ), "The ban has failed to reduce the average number of victims per gun
murder incident or multiple gunshot wound victims." (https://www.ncjrs.gov/txtfiles1/173405.txt) Furthermore, the rates of violent crime, homicide, assault, rape, theft have all dropped since the ban expired in 2004 (http://www.disastercenter.com/crime/uscrime.htm).

Have you ever met a real drug dealer, or criminal? I've encountered a few in my life. None of them would simply hand in their firearms if we repealed the 2nd Amendment. Take a look at Mexico. They have very Draconian gun laws, and their murder rate is MUCH higher than ours. Look at Australia - in 2007, five years after their gun ban was enacted, their Bureau of Criminology acknowledged that there is no correlation between gun control and the use of firearms in violent crime. Actually, you don't even need to look outside of the United States - read up on the Washington D.C. handgun ban.

Finally, let's suppose that the Aurora shooter was unable to get his hands on a firearm because our legislators made them illegal (and that's a pretty big hypothetical, because he probably would've been able to buy a gun on the black market anyways). Why do you think this would have made a difference? You don't think he'd just use explosives instead?